1. Field
The present invention relates to an electrochromic display that displays images by utilizing an electrochromic phenomenon.
2. Description of the Related Art
Electronic paper is getting more and more attention as a new display medium that combines the characteristics as paper, which is no need of information holding energy, can be securely saved, easily read, quickly readable and so on, and the characteristics as an electronic display capable of rewriting information and so on.
Various types are known as a display principle in the electronic paper. For example, it is a microcapsule type electrophoretic display method where capsules enclosing positively and negatively charged black and white particles are moved between electrodes. Further, it is a twist ball method where the direction of spherical particles colored in black and white are controlled. These methods perform display by utilizing a physical phenomenon.
On the other hand, there is known a method that performs display by utilizing a chemical phenomenon. Among others, one utilizing an electrochromic phenomenon is known where voltage is applied between electrodes to cause coloring or deletion by oxidation-reduction reaction. This is described in Japanese Patent Laid-Open No. 2002-258327 publication, for example.
In the case of an electrochromic display utilizing the electrochromic phenomenon, it is constituted that one substrate on which pixel electrodes are formed and the other substrate on which counter electrodes are formed are arranged in a facing manner, and an electrochromic layer and an electrolytic layer are formed between the both substrates, in which the electrochromic layer is formed on the pixel electrodes as described in Japanese Patent Laid-Open No. 2002-258327 publication.
However, as the number of pixels is increased and the pixels are made smaller in order to perform display of higher precision, risk of causing problems increases around pixel electrodes caused by short-circuit between adjacent pixel electrodes or short-circuit between the electrochromic layers on the adjacent pixel electrodes, and it becomes an obstacle in achieving higher precision.